The corneal endothelium in humans, primates and carnivores has but a limited regeneration ability. The regeneration of the endothelium is of importance in certain cases, such as for example after accidental or surgical damage to the corneal endothelium or epithelium; it is of importance in cases of degeneration of corneal endothelium, replacing keratoplasty. Fibroblast growth factor has been studied before (see Gospodarowicz et al, Proc. Nat. Acad. Sci, USA, 81, 6963-67, 1984 and also Bohlen et al, EMBO J., 4, 1951-56, 1985). It comprises two polypeptides which are basic FGF and Acidic FGF. These can be isolated from bovine brain, from the pituitary and from other organs. Both the acidic and the basic FGF are active in inducing the proliferation of various cultured cells including bovine corneal endothelial cells in culture. The prior art does not allow any valid prediction on the applicability of compositions of the invention for the purposes set out above and for other uses, as will be defined in detail hereinafter.